Rotational support as a function of redshift, measured as the ratio of the velocity at the effective radius and the constant velocity dispersion: v(r_e)/σ₀. Although studies based on ground-based near-infrared data (as described in Fig. 5) have found a clear, gradual decline in v/σ toward higher redshift, we find an interesting diversity among our sample of low-mass galaxies, with dynamically cold discs existing possibly as early as z ∼ 7.